Ranger 7 Takes 1st Image of the Moon by a US Spacecraft 50 Years Ago – July 31, 1964

byKen KremeronAugust 3, 2014

Ranger 7 took this image, the first picture of the Moon by a U.S. spacecraft, on 31 July 1964 at 13:09 UT (9:09 AM EDT) about 17 minutes before impacting the lunar surface. Credit: NASA/JPL-Caltech

As we remember the 45th anniversary of Earth’s historic 1st manned lunar landing last week by America’s Apollo 11 crew of Neil Armstrong and Buzz Aldrin on July 20, 1969, it’s likewise well worth recalling NASA’s pioneering and historic unmanned robotic mission Ranger 7 – that led the way to the Moon almost exactly 5 years earlier and that paved the path for the eventual 1st human footsteps on another celestial body.

Indeed the first critical robotic step to the manned landings was successfully taken when NASA’s unmanned Ranger 7 probe captured the first image of the Moon by a U.S. spacecraft 50 Years ago on July 31, 1964.

Ranger 7 took the milestone maiden picture of the Moon by an American spacecraft, on 31 July 1964, shown above, at 13:09 GMT (9:09 AM EDT) about 17 minutes before impacting the lunar surface on a suicide dive.

The history making image was taken at an altitude of 2110 kilometers and is centered at 13 S, 10 W and covers about 360 kilometers from top to bottom. The large Alphonsus crater is at center right and 108 km in diameter. Ptolemaeus crater is above and Arzachel is below.

Ranger 7 impacted out of view of the lead image, off to the left of the upper left corner.

“It looks as though this particular shot has been indeed a textbook operation,” William H. Pickering, the director of JPL during the mission, said at the time.

Guericke Crater as seen by Ranger 7
Ranger 7 B-camera image of Guericke crater (11.5 S, 14.1 W, diameter 63 km) taken from a distance of 1335 km. The dark flat floor of Mare Nubium dominates most of the image, which was taken 8.5 minutes before Ranger 7 impacted the Moon on 31 July 1964. The frame is about 230 km across and north is at 12:30. The impact site is off the frame to the left. Credit: NASA/JPL-Caltech

The purpose of NASA’s robotic Ranger program was to take high-quality pictures of the Moon and transmit them back to Earth in real time before being decimated on impact.

NASA Ranger 7 spacecraft. Credit: NASA/JPL-Caltech

The priceless pictures would be used for science investigations as well as to search for suitable landing sites for NASA’s then planned Apollo manned Moon landers.

It’s hard to conceive now, but 5 decades ago at the dawn of the Space Age no one knew what the surface of the Moon was really like. There were vigorous debates back then on whether it was even hard or soft. Was it firm? Would a landed spacecraft or human astronaut sink?

Last Ranger 7 images taken before impact on the Moon. They were taken by the number 1 and 3 P-channel cameras at 0.39 and 0.19 s before impact from an altitude of 1070 and 519 meters, respectively. The pictures are cut off because the spacecraft impacted the surface before completing the transmission. The top image was taken by the P3 camera and the bottom image by P1. The P3 image is about 25 m across. North is at 12:30 for both images. The impact occurred on 31 July 1964 at 13:25:48.82 UT. Credit: NASA/JPL-Caltech

Altogether the probe took 4,308 excellent quality pictures during its final 17 minutes before crashing into the Moon at 13:26 GMT (9:26 p.m. EDT) in an area between Mare Nubium and Oceanus Procellarum at a spot subsequently named Mare Cognitum at 10.63 S latitude, 20.60 W longitude.

The final image from Ranger 7 shown herein had a resolution of 0.5 meter/pixel.

Ranger 7 was launched atop an Atlas Agena B rocket on 28 July 1964 from what was then known as Cape Kennedy and smashed into our nearest neighbor after 68.6 hours of flight at a velocity of 2.62 km/s (1.62 miles per second).

The 365.7 kilogram (806 lb) vehicle was 4.5 m wide and stood 3.6 m (11 ft) tall and was the Block 3 version of the Ranger spacecraft. It was powered by a pair of 1.5 m long solar panels and was equipped with a science payload of six television vidicon cameras transmitting data via the pointable high gain antennae mounted at the base.

Ranger 7 was the first successful mission in the Ranger series. The flight was entirely successful and was followed by Ranger’s 8 and 9. They were built by NASA’s Jet Propulsion Laboratory, Pasadena, California.

Here’s a short 1964 documentary chronicling Ranger 7 titled “Lunar Bridgehead” that truly harkens back to the 1950s and 1960s and sci fi movies of the time. No wonder since that’s when it was produced.

Video Caption. This 1964 documentary titled “Lunar Bridgehead produced by NASA’s Jet Propulsion Laboratory, Pasadena, California, chronicles the moments leading up to and following the Ranger 7 mission’s lunar impact 50 years ago. Credit: NASA/JPL-Caltech

During the 1960’s NASA implemented an ambitions three pronged strategy of robotic missions – including Ranger, Lunar Orbiter and Surveyor – that imaged the Moon and studied it’s physical and chemical properties and supported and enabled the Apollo program and led directly to Neil Armstrong stepping onto the alien lunar landscape.

Three members of the Ranger 7 television experiment team stand near a scale model and lunar globe at NASA’s Jet Propulsion Laboratory (JPL). From left: Ewen Whitaker, Dr. Gerard Kuiper, and Ray Heacock. Kuiper was the director of the Lunar and Planetary Laboratory (LPL) at the University of Arizona. Whitaker was a research associate at LPL. Heacock was the Lunar and Planetary Instruments section chief at JPL. Credit: NASA/JPL-Caltech

Read more about pathfinding space missions in my earlier space history story about Mariner 10 – the first space probe to ever carry out a planetary gravity assist maneuver used to alter its speed and trajectory – in order to reach another celestial body – here.